Ann’s husband, Dean Wetter, was arrested for physically attacking Nancy’s children while the siblings were performing a show together in Auburn, Wash., last August. The incident is reported to have occurred after one of the kids left a tour bus door open, meaning a pet dog could have escaped -- which threw Wetter into a rage. He was detained after police were called.

The sisters’ relationship deteriorated to the extent that Ann called the last 20 shows of the tour “hell,” while Nancy described them as “excruciating” – and the pair used separate dressing rooms for the first time since they began working together in the ‘60s. Since then, Ann has launched a solo tour while Nancy has formed a new band, Roadcase Royale. The Wilsons are said to have only communicated via text.

“I wouldn’t say it’s a temporary hiatus," Ann told Rolling Stone. "I would say it’s a hiatus. We don’t need that little qualification in there. When I came offstage and Dean told me what happened, the first thing he said was, ‘Go onto Nancy’s bus and clear the way, because I want to apologize.’ I went over, and everyone in the Heart camp was sitting around. They wouldn’t listen. I know him and I know he was really provoked. It was wrong of him to get into it, but he’s a person of extremely high moral fiber. It was just totally unfortunate all round.”

Wetter pleaded guilty to two non-felony assault charges last month, and a deal means he won’t face prison time when he’s sentenced on April 14. Pointing out that parents have an obligation to inform police about assault situations, Nancy said, “I don’t think it was cool of her to try to cover for him. I thought, if he was an adult, he would face it and try to explain the behavior. But that’s never happened.”

She added that she found Wetter “hard to know” in the two years since his marriage to Ann. “He’s one of those crankpots – he’ll kind of mouth off about kids," she said. "He’s a guy that had some issues that really came between me and wanting to see him anytime soon.”

“He’s a different animal from anyone else who’s ever come into our family," Ann countered. "She never really understood him. He was demonized before we got married because he’s a free spirit. He’s completely blunt, honest and open. People take it personally.”

The incident seems to have brought an underlying career dispute to the surface. Ann admitted that she and Nancy “no longer had a shared vision” for Heart over the past several years ago. “We didn’t want to see ourselves as an old, has-been legacy band, just going out again and again," she said. "I saw that happening more and more. She has a vision of playing the same old meat-and-potatoes set in Europe. It can just go on forever.”

The singer said she wanted to avoid becoming “a static thing that’s going to ride into obscurity without at least trying to evolve.” Ann added, “I don’t mean to say she’s wrong. We just differ, that’s all.”

It seems that the door isn’t locked against a reunion, with Nancy insisting she was “really happy” for her sister if she’s in a good marriage. “It’s been more negative than it needed to be, but I’m willing and ready to get back into a dialogue, with Ann in particular, about if we’ve still got Heart. I just know in my gut that me and Ann are going to be fine.”

“I do see a positive way forward, and that’s our friendship," Ann said. "Nancy and I didn’t do this thing. Nobody in this situation is evil. Nancy and I love each other. We want to be friends. My side really hurt her side, her side really hurt my side. We’ve got to let those heal, and get some counseling.”